As one skilled in this field of technology appreciates, the ability to steer a jet propelled water craft when the throttle is cut and no thrust is being produced by the jet nozzle is non-existence without some type of safety mechanism that allows a rudder to operate during this envelope of the propulsion cycle. There are sun dry mechanisms that have been developed over recent years that are design to provide rudder steering on these types of recreational water craft. These heretofore known devices have not been designed as a safety mechanism to address the problems incidental to off throttle steering, which is essentially the problem that this invention addresses. Obviously, without such a steering device, the water craft is prone to causing accidents since the momentum of the water craft and its inertia caused by the thrust produced by the jet stream of water just prior to being cut will propel the craft in that given direction. For sure, anything in its way will meet with some type of catastrophe. Since these water crafts are particularly desirable for recreational purposes, the mechanism that is designed to provide this auxiliary steering must be simple and not interfere with the handling of the craft. For example, if the auxiliary steering mechanism remains in the water and produces drag, the drag would adversely affect the handling of the craft and in some instances create a hazard by not allowing the water craft to slide sideways but rather causes the water craft to roll over throwing the operator from the craft. This obviously detracts from the water craft's ability to produce the maneuvering desirable. Several of the devices that have attempted to solve this problem are detailed in the prior art and are discussed below.
U.S. Pat. No. 3,976,026 granted to Eastling on Aug. 24, 1976 entitled "Slow Speed Steering Control for Jet-Powered Water Craft" shows a steering plate (rudder) mounted below the exhaust port of a jet propelled water craft. While it includes a spring biased rudder, the rudder remains in the water below the exhaust port at all times and the spring serves to allow the rudder to displace slightly upward upon hitting a foreign objects. Unlike the present invention the rudder remains in the water at all times below the exhaust port and the stream of flow discharging therefrom.
Another example of an auxiliary rudder is disclosed in U.S. Pat. No. 3,982,494 granted to Posti on Sep. 28, 1976. The rudder for this jet powered water craft is in fact a twin rudder parallelly mounted adjacent the outer periphery of the jet nozzle. A piston responding to the velocity in the jet stream mounted within the nozzle serves to raise the twin rudder above the nozzle and out of the water. While it is intended to provide a similar function as that being provided by the present invention, it is complicated and requires a motive force by virtue of the piston to actuate the rudder. Another draw back to this design is that the rudder has to overcome the force of the piston to be raised in the event that the rudder hits a foreign object. Notwithstanding that the force on the piston is relieved to allow the rudder to drop into the water in its operative position, it still must overcome whatever force is being sensed by the piston while in a slow moving mode. Obviously, when the throttle is full off, the force is removed and presumably the rudder will lift in the event it meets a foreign object.
U.S. Pat. No. 4,779,553 granted to Wildhaber, Sr. on Oct. 25, 1988 entitled "Automatic Rudder for Outboard Jet Motors" exemplifies still another embodiment of an auxiliary rudder intended to operated during the low speed and/or power-off mode of operation. In this embodiment the rudder is pivotally mounted to a base that fits over the steering nozzle and bolted thereto and is configured to drop by virtue of gravity when the plume from the jet nozzle decays or ceases. The engine is an outboard motor whose propulsion portion is fully emersed in the water. The rudder in this structure is always remains in the water and is never raised out of the water.
U.S. Pat. No. 5,167,547 granted to Kobyashi et al on Dec. 1, 1992 entitled "Rudder For Watercraft" discloses an auxiliary rudder designed for a water jet propelled water craft the includes a control for removing the rudder out of the water during high speed operations and includes a spring bias that allows the rudder to be displaced upon hitting a foreign object. It doesn't utilize a plate or disk to activate the rudder as is disclosed in the present invention.
The problems with the prior art auxiliary rudders is that the mechanism is either too complex, doesn't exit the water while not in use, or doesn't have the force capability to properly position the rudder, or is too slow in its deployment. Aside from the mechanical differences and differences in design philosophy, these prior art devices just described do not have as its primary objective the safety of the operator and/or occupants as is the case of the present invention.
This invention is particularly related to the throw back rudder; i.e. the type of rudder that is forced out of the water by the force of the water stream discharging from the jet nozzle of the water craft. I have found that I can obviate the problems noted above by designing the rudder to be biased in the downward position by a spring and including a plate-like member that substantially fits or is contiguous with the jet nozzle port when the rudder is deployed. The rudder is mounted to the jet nozzle and rotates therewith for providing the steering and is located downstream of the jet nozzle. The plate-like portion's relative position with respect to the nozzle's exhaust port is that it lies in line therewith and virtually covers the port so that the jet stream impinges the plate and blows back the rudder out of the path of the jet stream. The rudder is in coincidence with the center line of the jet nozzle's exhaust port to assure accuracy in the steering. It is contemplated that the edge of the plate can be contoured so that it provides a space between the wall of the exhaust port to define an opening to allow for a given amount of the flow stream to penetrate therethrough for allowing the rudder to be deployed in the steering mode at low speeds. The area of the gap defined by this contour determines the speed at which the rudder is deployed. In another embodiment of this invention the plate-like member is contoured with a concave surface facing the jet stream discharging from the jet nozzle so as to reverse the flow of the jet stream and cause reversing of the water craft. Essentially, other than the reversing feature, this embodiment provides all of the features that are provided by the embodiment described in the immediate above paragraphs.
My invention is characterized as being simple to fabricate, install, maintain, is reliable and will almost instantly deploy in the steering position without incuring any delays in the transition from the non-deployment to the deployment positions. This has the advantage of affording a safety factor to the rider and/or occupants inasmuch as it prevents accidents and hence, eliminates blunt force trauma that is the cause of fatalities and the concern in the industry.